fixing your desktop

How to cool down a Macbook Air … fast

Is your Macbook Air overheating? Here’s a technique I’ve been using for the last couple of years, works everytime. I suspect it still works on the new models – I *suspect* they have the same basic design flaws as the original, from looking at the case.

Problem: vents in wrong place

Those vents along the rear underside of the case … don’t work. I don’t know how they ended up there, but I suspect it was a triumph of “looks” over “not breaking the expensive laptop” (until Apple patched OS X, just running Flash was enough to cause OS shutdowns on a regular basis).

Solution: assume launch position…

Grab your Air, hold it at the hinge (so the lid doesn’t slam down and switch the laptop off), and tilt it towards you 90 degrees.

i.e. the keyboard half of the laptop should be vertical, resting on the long, bottom, edge.

The vents now vent air straight up – unimpeded – instead of down-and-out (impeded by the case itself).

Result: fast cooling

I can usually get an Air that’s been running “hot” (fans very loud and noisy) for minutes / hours to cool down in under 60 seconds using this technique.

Why does this matter?

Well … once an Air is cool, it tends to stay cool. i.e. it’s crap at bringing it’s own temperature down, but it’s got enough oomph to *keep* it at whatever temp is current. So, manual intervention fixes the problem.

Super-fast cooling (a.k.a. “PANIC!”)

What do you do if your Air starts beeping?

(hint: this is the never-actually-explained-to-you hardware warning that “your CPU is about to melt. Cool it down NOW or buy a new laptop”. I wonder how many people realise what’s happening when they hear that screeching, high-pitched beep and think “WTF?”)

As above, only shut the lid too.

This may seem counter-intuitive – after all, this will reduce the air-surface of the Air by about 50%, reducing it’s ability to cool down.

In practice, although that’s true at low temperature, at high temperature the heat is already concentrated in the top-left corner of the keyboard (where the CPU sits) – and most of the case is too far away to help.

In practice, closing the lid causes OS X to suspend processes, which normally takes enough load of the CPU that the laptop / hardware is able to cool itself MUCH faster – but only if you’re holding the whole laptop vertically, with the vents pointing upwards.

I’ve found this normally cools an Air from “max fans” to “silent” in under 15 seconds.

4 replies on “How to cool down a Macbook Air … fast”

I admit I’m amused. You can take a CPU fan off a BIOS-using x86 CPU windows PC, and it will shut down in moments. And slow fans will lead to CPU throttling.

EFI, by and large, doesn’t support this. It really, really is solving the wrong issues…

This really works on my MBA. I use it attached to a monitor and keyboard so I prop it up on a stand with the lid closed and the vents facing up. The fan very rarely speeds up now. (which was annoying me) Hopefully the low fan speed (1800rpm) should be enough to keep out in falling dust.

I lay it out flat when I’m finished.

Splendid. Why didn’t I think of that :-)

What a ridiculously easy solution! It works great! Like Budda Dave, I work with an external monitor, so the lid is shut and the computer stays vertical when I work. Thanks!

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